As a reception front end circuit that is provided in a communication apparatus, one having a folded load down converter circuit that includes a mixer circuit, a current mirror circuit and a load circuit is known. In the folded load down converter circuit, the current mirror circuit turns back the output of the mixer circuit and the load circuit is connected to the output that is turned back by the current mirror circuit. As a reception front end circuit, one is known further having a detection circuit that carries out detection from the input signal or the output signal of the folded load down converter circuit; a smoothing circuit that smoothes the output signal of the detection circuit; and a reference comparison circuit that compares the output signal of the smoothing circuit with a predetermined reference voltage. The reception front end circuit further has a bias control circuit that controls a bias of the folded load down converter circuit depending on the comparison result of the reference comparison circuit.